1. Field of the Invention
This invention relates to wireless communications, and more specifically to using a policy control function (PCF)/policy decision function (PDF) for multimedia broadcast/multicast system services (MBMS).
2. Background of the Related Art
Conventional wireless communication systems suffer from the problem of static, limited traffic classification capability. A Quality of Service (QoS) control may be provided through QoS profiles contained in a Home Location Register (HLR) of the system. This has the disadvantage that the network applies the same HLR based QoS for all communication services. Such static HLR based control is not service-aware. It is not possible to achieve differentiated treatment for different types of service usage within one traffic class and the network is sufficient only for short-term simple communication services.
The 3rd Generation Partnership Project (3GPP) has attempted to provide for policy based admission control in Release 5 of the 3GPP TR 23.917 specifications “Dynamic Policy control enhancements for end-to-end QoS”, the contents of which are incorporated by reference herein. The specifications include a Policy Control Function (PCF), which although a separate logical entity from the Proxy Connection State Control Function (P-CSCF), is described as being a part of the P-CSCF in Release 5. Consequently, policy based admissions control is only available for communication services provided through the IP multimedia subsystem (IMS) and only the IMS may request resources of the radio access network (for example, Global System for Mobile Communications (GSM) or Universal Mobile Telecommunications System (UMTS)) for the communication services.
In Release 5 of the 3GPP TR 23.917 specifications, a policy control function is only applicable for IMS and tightly linked to the Session Initiation Protocol (SIP) session control. This does not enable a generic service policy to be applied to both IMS and non-IMS services, such as multimedia broadcast/multicast system (MBMS) service.
Moreover, the QoS authorization phase in some current methods only work with MBMS multicast mode. In MBMS multicast mode the mobile device (i.e., User Equipment (UE), Mobile Station (MS), Mobile Node (MN), etc.) must send an IGMP Join message to the Gateway GPRS Service Node (GGSN) to indicate its wish to join to a multicast service. This Join message will then initiate the QoS authorization procedure, i.e. the COPS REQ (Common Open Policy Service Request) message to the PCF to exchange the handle. With MBMS broadcast the UE does not send an IGMP Join message. Therefore, the QoS authorization phase must be initiated by the Broadcast/Multicast-Service Center (BM-SC).